Firstly, when recovering data it is recommended connect the drives directly to a PC running the recovery (via SATA) rather
than using some sort of USB boxes which are known to reduce speed, compared to direct SATA connection.
Also, it is advisable to check S.M.A.R.T status of the disks coming from the NAS in question before recovering data and
create disk image files at the slightest sing of faulty disk(s), for example bad sectors or even reallocated sectors are revealed.
RAID recovery, that is recovery of RAID configuration parameters like block size, start offset and disk order, usually takes a lot of time.
NASes, and Seagate BlackArmor including, typically use the Linux md-raid driver to manage RAID meaning that in most cases you should try
to "read" md-raid metadata first to obtain NAS configuration,
as described in our NAS recovery tutorial.
Only if it fails, try a full-scale RAID recovery.